BTFDBB: BTF Database Bonn and Measurement Lab

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UBO2014 Datasets

Update (2014/12/11): The synthetic data has just been added!

Here you can download the material appearance as compressed BTF files for a number of material samples that have been captured using the Dome I setup of our department. Per material sample, a full BTF has been measured using the bi-directional sampling of 151 viewing directions and 151 lighting directions, where the cameras are uniformly distributed on a hemispherical gantry. For lighting, we use the flashes of the cameras.

Currently, our database consists of 7 semantic categories. Each of these 7 material categories contains measurements of 12 different material instances for being capable to represent the corresponding intra-class variances. Per material sample, a full BTF has been measured using the bi-directional sampling of 151 viewing directions and 151 lighting directions. Consequently, a total of 22,801 images have been acquired for material samples with a size of 5 cm x 5 cm with spatial resolution of 512 x 512 texels. The available BTFs contain the central 400 x 400 texels (corresponding to an area of approx. 3.9 cm x 3.9 cm).

We offer two types of BTFs: Decorrelated Full-Matrix-Factorization (DFMF)-BTFs and BTFs resampled with respect to the surface geometry which has been measured using structured light. This allows rendering realistic silhouettes and helps to reduce compression artifacts which are caused by a blurring of surface details. This blurring results from parallax effects at regions significantly protruding from the modeled reference surface.

Besides the BTF data, there are archives of synthetic renderings for each of the materials under various environmental illuminations. Per material there is an uncompressed tar archive containing folders for each of the five used environments. Inside these subfolders there are high dynamic range renderings in the OpenEXR format, whose filenames have the form: img_phi_theta_distance_envrot.exr

envrot represents the rotation of the environments (used to increase the intra-class variances)

All datasets are free to use, modify and re-distribute for research and scholarship purposes. Furthermore, permission is granted to publish images made using the BTF data in a scholarly article or book, as long as proper credit is given to the University of Bonn's BTF Database. Any usage of the datasets for commercial purposes is not allowed without our permission and in some cases the permission of third parties. For more information about the databases, please refer to:

You can access the data either using your web browser and download directly from this page: http://cg.cs.uni-bonn.de/btf. The data is provided in a compressed binary format. Examplary code for reading and decoding these files is available on github.